Every Democratic member of Congress and every Democratic governor all get the superdelegate stamp. Then there are "distinguished party leaders," a group that includes former presidents and vice presidents. The rest are members of the DNC — typically the chair, vice chairs, Democratic mayors and other party leaders.

Superdelegates have free rein but generally line up behind the candidate who wins the most delegates from state primaries and caucuses, no matter what side they're on at the beginning of the election season.

In the 2008 primary, Clinton also started out with the most superdelegates. But as another virtually unknown senator surprised the country and began to win, some of her superdelegates began to bolt.

So yes, currently Clinton still has quite the superdelegate backing, but we're still at the very beginning of what could be a long primary. If the Vermont senator's coalition builds, and he's able to grab more primary and caucus wins, he may find himself with the establishment he rails against so much actually on his side.